Penicillin-binding proteins (PBPs) are a group of enzymes involved in assembly of the cell wall in both gram negative and gram positive bacteria. They are characterized by their affinity for and binding of penicillin. There are a large number of PBPs, usually several in each organism, and are found as both membrane bound and cytoplasmic proteins.
Staphylococcus aureus (SA), a gram positive bacterium, has been linked to several pathologies. Treatment and management of this disease and other bacterial infections is increasingly difficult due, at least in part, to the emergence of antibiotic-resistant bacterial strains, for example, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant methicillin-resistant Staphylococcus aureus. 
S. aureus normally produces four penicillin-binding proteins (PBPs), which are know to be susceptible to modifications by β-lactam antibiotics, which can lead to bacterial death. The product of the gene mecA from MRSA is another penicillin-binding protein (PBP), designated PBP2a. Unfortunately, PBP2a has been found to be resistant to the action of the vast majority of commercially available β-lactam antibiotics. Furthermore, PBP2a is capable of taking over the functions of the other PBPs of S. aureus in the face of the challenge by β-lactam antibiotics.
Accordingly, new compounds and compositions are needed that are capable of inhibiting bacteria, such as antibiotic-resistant bacterial strains. New compounds and compositions that can be used to treat bacterial infections are also needed. Additionally, a model for screening and identifying anti-bacterial agents against evolving new bacterial strains would aid researchers in treating infectious diseases, such as those caused by antibiotic resistant strains of bacteria.